/**
 * Created by 泽汐、 on 2017/6/30.
 */
    //图片上传预览    IE是用了滤镜。
    function previewImage(file,divID,imgID,imgDel)
    {
        var MAXWIDTH  = 300;
        var MAXHEIGHT = 200;
        var div = document.getElementById(divID);
        if (file.files && file.files[0])
        {
            div.innerHTML ='<img id='+imgID+'>';
            var img = document.getElementById(imgID);
            img.onload = function(){
                var rect = clacImgZoomParam(MAXWIDTH, MAXHEIGHT, img.offsetWidth, img.offsetHeight);
                img.width  =  rect.width;
                img.height =  rect.height;
              //  img.style.marginLeft = rect.left+'px';
               // img.style.marginBottom = rect.top+'px';
                img.style.border = '2px solid rgb(229,229,229)';
            }
            var reader = new FileReader();
            reader.onload = function(evt){img.src = evt.target.result;}
            reader.readAsDataURL(file.files[0]);
        }
        else //兼容IE
        {
            var sFilter='filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale,src="';
            file.select();
            var src = document.selection.createRange().text;
            div.innerHTML = '<img id='+imgID+'>';
            var img = document.getElementById(imgID);
            img.filters.item('DXImageTransform.Microsoft.AlphaImageLoader').src = src;
            var rect = clacImgZoomParam(MAXWIDTH, MAXHEIGHT, img.offsetWidth, img.offsetHeight);
            status =('rect:'+rect.top+','+rect.left+','+rect.width+','+rect.height);
            //div.innerHTML = "<div class=divhead style='width:"+rect.width+"px;height:"+rect.height+"px;margin-top:"+rect.top+"px;"+sFilter+src+"\"'></div>";
            div.innerHTML = "<div class=divhead style='width:"+rect.width+"px;height:"+rect.height+""+sFilter+src+"\"'></div>";
        }
        var imgDel = document.getElementById(imgDel);
        imgDel.style.display = "";
    }
function clacImgZoomParam( maxWidth, maxHeight, width, height ){
    var param = {top:0, left:0, width:width, height:height};
    if( width>maxWidth || height>maxHeight )
    {
        rateWidth = width / maxWidth;
        rateHeight = height / maxHeight;

        if( rateWidth > rateHeight )
        {
            param.width =  maxWidth;
            param.height = Math.round(height / rateWidth);
        }else
        {
            param.width = Math.round(width / rateHeight);
            param.height = maxHeight;
        }
    }
    param.left = Math.round((maxWidth - param.width) / 2);
    param.top = Math.round((maxHeight - param.height) / 2);
    param.width = 280;
    param.height = height*(280/width);
    return param;
}